1. Field of the Invention
The present invention relates to reciprocating cutter type trimmers and more particularly to a reciprocating cutter type trimmer in which a pair of upper and lower blades are subjected to reciprocation by way of power transmission means such as eccentric cams.
2. Description of the Prior Art
In a reciprocating cutter type trimmer used for trimming bushes and grass, such as clipping weeds at ridges and service waterways, mowing lawns and trimming hedges, the output of a power source such as an internal combustion engine arranged at one end of an operation rod is typically transmitted to a blade unit through a power transmission unit to mutually relatively reciprocate a pair of upper and lower elongated blades in the longitudinal direction to cut bushes and grass.
This type of trimmer having two reciprocating cutters to be reciprocated has hitherto been well known as shown in, for example, FIG. 4. FIG. 4 is a side sectional view of the trimmer according to a conventional example. Upper and lower blades 61 and 62 which are each formed of a generally elongated plate protrude from one side of a case 63 outwardly (frontally) thereof, and they are supported on upper and lower blade guide plates 64 and 65 by means of a plurality of fixing members B so as to be mutually slidable. The output of a power source is transmitted to the blades 61 and 62 through power transmission means so that the blades may be reciprocated to and fro in opposite phases to each other.
In the aforementioned conventional reciprocating cutter type trimmer, when the blades are worn out or broken and exchange or grinding thereof is needed, exchanging of the blades must be done, in the case of a separation type blade, by releasing the plurality of fixing members and then removing the upper and lower blade guide plates. In the case where the blade is not of the separation type (an integral type blade), the case even has to be disassembled and the power transmission member even has to be removed in order to perform exchanging of the blade. Disadvantageously, in any case, exchanging of the blade is very troublesome work and, besides, loss of parts is liable to happen during disassembling, exchanging and assembling work. The present invention has been achieved to solve the above problems of the conventional trimmer and it is an object of the present invention to provide a reciprocating cutter type trimmer which can facilitate exchanging of blades, prevent loss of parts during blade exchanging work and which is simplified in construction.
According to the present invention, to accomplish the above object, in a reciprocating cutter type trimmer comprising a power transmission unit for conversion of rotary motion into linear reciprocation, the present invention provides a case accommodating the power transmission unit, blades protruding from the case frontally thereof and being reciprocative to and fro under the application of power transmitted from the power transmission unit, and upper and lower blade guide plates protruding from the case frontally thereof and being operative to support the blades from above and below, the blades being each divided into a power transmission member coupled to the power transmission unit and an edge member and constituting a separation type blade in which the blades are individually removable, at least one of the upper and lower blade guide plates is rotatably pivoted on the case, and a connecting part of the separation type blade is disposed frontally of a pivotal portion formed at the inner end of the rotatable blade guide plate. As a specified example, the pivotal portion includes a pivotal shaft mounted to the case, and a curved portion formed by winding the inner end of the rotatable blade guide plate about the pivotal shaft.
In the reciprocating cutter type trimmer according to the present invention constructed as above, when the edge member of the blade is to be exchanged, the blade and the part connectable to the power transmission member (i.e., the whole edge member) can be exposed by turning the pivoted one blade guide plate outwards and only the edge member can be removed and exchanged easily.